In conventional numerical control systems, in particular for machine tools and robots, a motion sequence for a plurality of axes is programmed for a sequence-controlling base interpolator through so-called base interpolation segments having a side-by-side arrangement. To this end, in conformance with the participating axes of motion, one can select from a limited number of configurations, as well as among various interpolation methods, such as linear, circular, and spline interpolation. As a rule, motion segments and associated interpolation methods, as well as the feed function are performed as block-orientated functions. For this purpose, a control data block contained in an existing control data program or parts program is processed. The input variables of the base interpolation are always the path parameters; the output variables are always either the setpoint position or the corresponding velocity tool path feedrate.
For complex multi-axis motion, e.g., a complex machining process, several axial reference variables must be made available, for which a plurality of synchronously executed channels, so-called NC channels when referring to machine tools, are necessary for the cutting motion, the feed motion, and the infeed motion of gear slotting. To make available such axial reference variables, a reference-value interpolation that is directly coupled to geometric data production does not yet exist at the present time for a process control or closed-loop process control. Moreover, no CNC-integrated monitoring system that is directly coupled to geometric data production is known.
Typically, closed-loop process control parameters or monitoring control parameters can only be adapted to changing technological process conditions by coupling them to a block change within a control data program. That is why one is only able to program relatively rough monitoring values, which do not apply exactly to the entire run of the machining segment, over the entire machining segment, an interpolation segment. It is only at a block change that one is able to adapt control parameters or reference values to technological process conditions. When working with a conventional base interpolation, as a rule, the geometry of a nominal path must be broken down into quite a number of path segments or blocks. However, this does not allow any high-speed machining with high tool path feedrates, as blocks have to be preprocessed frequently and, therefore, entail considerable computational outlay. In addition to this, under known methods heretofore, a monitoring limiting value is activated already at the instant when, for example, a milling cutter is replaced as an active tool in the milling spindle or is activated in the processing sequence. However, the monitoring reference value remains constant during a control program block.